Remote control and signaling system for railway installations



Jan. 5, 1937. A BECQ; ET AL 2,066,513

REMOTE CONTROL AND SIGNALING SYSTEM FOR RAILWAY INSTALLATIONS Filed Jan. 18, 1936 2 Sheets-Sheet l Fig.1

INV/ENTORS I ANDRE 55cc; PAUL N ICOLAS wiafivg ATTORNEYS Jan. 5, 1937. A. BECQ ET AL REMOTE CONTROL AND SIGNALINGv SYSTEM FOR RAILWAY INSTALLATIONS 2 Sheets-Sheet 2 Filed Jan. 18, 1936 NTORS' Patented Jan. 5, 1937 UNITED STATES PATENT OFFICE REMOTE CONTROL AND SIGNALING SYS- TEM FOR RAILWAY INSTALLATIONS Application January 18, 1936, Serial No. 59,684 In France February 19, 1935 '7 Claims.

This invention is for improvements in or relating to remote control and signaling systems for railway installations.

I One object of the present invention is to provide an improved remote control or signaling system for railway installations whereby the operation of warning signals, of track points or of any other desired device may be effected under the control of and in advance of a vehicle travelling along the railway track.

Another and more specific object of the invention is to provide a remote control or signaling system for railway installations which is particularly adapted for operating alarm devices under the control of and in advance of a train, travelling along the track, such as for notifying of the approach of a train to a level crossing.

Such a system is described in the copending application Serial No. 15,962 of April 12, 1935,

go wherein a generator inducing an alternating current in the rail and a separate loop receiving the current circulating in the rails are provided. As this current is of variable phase, depending on whether the road before the train is short- 25 circuited or not, and depending on the distance from this shortcircuit, there has also been provided on the train a receiver supplied differently by said generator on the one hand, and on the other hand by said loop in order to measure the 30 dephasing between the currents from these two sources and to actuate a signal on the locomotive as soon as the dephasing exceeds a predetermined value.

A further object of the invention is to pro- 35 vide a remote control or signaling system for railway installations which is so arranged that a controlling action or signal indication will be effected at a desired point irrespective of the state of the track in advance of a vehicle travel- 40 ling along the track and which controls the establishment of the said controlling action or signal indication.

The invention may be carried into practice in various Ways. Preferably there is employed as 45 transmitting agent for effecting the remote control or signaling action, a current of audio-frequency (400 to 2,000 periods for example) which is induced in the rails of the track itself by an alternating current generator assembly supply- 50 ing current to a coil carried on, and preferably in the front of, the train travelling along the track and which is to effect the control.

The currents which are induced in the rails by the alternator and coil carried on the train are 55 propagated in advance of the train by the complex circuit which is formed by the two rails and by all that is interposed between them (conduction by the ballast, short-circuit formed by the axles of a preceding train, shunting rods, etc). The circuit is closed immediately by the first .5 axles of the train itself.

The currents induced in the rails of the track in advance of the train are those which are principally used in accordance with the present invention, in spite of their essentially variable na- 10 ture, for the purpose of controlling electro-mechanical members, signals, track points, etc. In order to obtain a proper functioning of the said controls in spite of the variable nature of the track currents, there is utilized in accordance 15 With the invention a combination of at least two relays, at least one of which is responsive to the current circulating in the rails of the track, and at least one other of which is responsive to the voltage between the said rails towards the position along the track where the device to be controlled is located. According to the nature and the state of the track on the other side of the device to be controlled, such as a signal, relatively to the vehicle effecting the control, and according to the obstacles which may be found there, one or the other of the said quantities to which the relays are responsive will, in fact, preponderate. The arrangement according to the invention is then such that the device to be controlled, such as a signal, will be actuated by one or the other at least of the said relays.

The invention also comprises accessory means for effecting the repetition of the signal indications etc. made, either at other points along the track or on the train itself. This is preferably effected by utilizing a change in the impedance of the section of the track in front of the train to operate an indicating device showing this change, said indicating device being carried, for 40 example, on the train.

The invention finally comprises various methods of carrying the same into practice and in particular the establishment of certain relations between the time constants of the operating relays in order to permit them to Work under perfectly definite conditions. The above and other features and advantages of the invention will be more clearly understood from the following detailed description of preferred embodiments of the invention which is given, by way of example, with reference to the accompanying drawings, in which:

Figure 1 illustrates diagrammatically one preferred embodiment in accordance with the invention including the entire circuit comprising the emitter, the track and the signal to be actuated, and

Figures 2, 3 and 4 represent various embodiments to be employed in an installation of receiving circuit according to Figure 1.

With reference to Figure 1, there is represented diagrammatically therein the front of a train A travelling along a track in the direction of the arrow F, and which is approaching a signal S. (1 represents the first axle of the train, G an alternating current generator carried by the train A and which furnishes a current of audio frequency, B a coil through which the said current flows and from which a current is induced in the rails of the track. At C and L there are shown respectively a self-inductance and a capacity which permit a more efiicient action being obtained by ensuring the resonance of the output circuit of the alternator.

In order to ensure good conductivity of the assembly formed by the rails of the track and to avoid bad contacts which are sometimes made at the fish-plates represented by D, the said fish-plates are preferably shunted by a small portion of the conducting cable,' according to known methods when it is desired to form a track circuit. Nevertheless, it is not necessary in an installation in accordance with the invention to provide insulating joints, and the installation of the track in the vicinity of the signaling devices is therefore considerably simplified.

Figure 2 illustrates the section of track MN adjacent the signal S and a circuit diagram of a receiving circuit in accordance with the invention for controlling the signal S. The said receiving circuit comprises two relays, the one R which operates in response to the voltage U between the rails of the track and the other R1 which operates in response to the current I in the rails. It is evident that if the impedance of the track circuit beyond MN is great, I will be small and U comparatively high. The contrary will be the case if this impedance is small.

The operation of the arrangement is as follows: The voltage relay R is actuated through a transformer T and a circuit LC substantially tuned to the frequency of the current transmitted from the train. The resonance potential taken at the terminals of the self-inductance L between the points P and P supplies the coil of the relay R. The latter might be an alternating current relay, but it is generally more convenient to use, in the embodiment illustrated, a direct current relay mounted in series with any suitable rectifier V, such as electronic valve, an oxide rectifier etc. The relay R, when it operates, closes a contact K and supplies current to the signal S.

The said signal S may be controlled in the same way by the contact K1 connected in parallel with the contact K and carried by the relay R1. This latter relay is'supplied, through a rectifier V1, by the resonance potential taken at the terminals P1, P1 of a tuned circuit B1, C1 coupled inductively with the track. The coil B1 will be of sufficient dimensions to take the necessary energy.

The signal S may thus be operated by either one of the relays R and R1 according to the nature or the state of the track in front of the signal S.

There may also be arranged in accordance with the invention, in parallel or in series with the signal S (preferably in series if it is simply a question of a lamp) other signal devices S, S" etc., at any desired points, such as for giving an optical control to the driver of the train, indications to users of a road, such as at a level crossing, etc. It is also possible to effect the said control on the train itself by combining the above-described arrangement with means for changing the impedance of the track with a view to causing the operation of a receiver indicating such change carried by the train. It may then be sufficient for the track to be short-circuited between MN as soon as the signal S has operated. This may be obtained, for example, as illustrated in Figure 3, by adding a supplementary contact K and K1 to each of the two relays R and R1. These two contacts will be mounted in parallel like the contacts K and K1 and there will be given to the two relays suitable time constants. The operation of the arrangement may then be as follows: On the approach of the train to the signal S and according to the nature of the track, one or the other of the two relays R and R1 will act first. Let it be supposed that the relay R is the first to operate. The contact K operates the signal S and the contact K short-circuits MN. This short-circuit has two eifects. Firstly to de-magnetize the relay R and secondly to cause a larger current to pass into the track, that is to say, to excite in its turn the relay R1. The arrangement will be such that the relay R1 is sufficiently rapid in operation to operate before the relay R becomes de-energized. To this end, it will be sufilcient to give the latter a retardation of a few tenths of a second in releasing. Under these conditions, contacts K1 and K1 will be closed before contacts K and K open. Contact K1 will maintain the short-circuit between MN and contact K1 will maintain the signal S in operation until the train has passed through. After the passing of the train, the two relays R and R1 will obviously return to rest since there will no longer be either current or voltage in the track.

It will readily be understood that the operation of the arrangement will be even more simple if it is the relay R1 which operates first. This will take place, for example, if there is another train on the track a little beyond the signal S. In this case, the contacts K1 and K1 will act immediately on the signal S and on the shortcircuit. The transformer T will be short-circuited and the relay R will not operate at all.

It is evident that when such a combination is employed, the same audio frequency generator may be employed both to control the signal S in accordance with the present invention and to ensure the repetition thereof on the train.

It will also be understood that many modifications of the above arrangements may be made within the scope of the invention. Thus, the relays R and R1 may be employed not to close a short-circuit of the track, upon operation, but to open one. On such a case, it is suificient to provide the relays R and R1 with contacts K" and K1 arranged to effect the control action by opening. The circuit arrangement may then be such as illustrated in Figure 4. With reference to this figure, in the absence of current and potential in the track, the two contacts K and K1, which are still mounted in parallel, are open and the signal S is at rest. The two contacts K and. K1, on the contrary, are connected in series between the two rails of the track and are normally closed. The rails are consequently normally short-circuited. When a train arrives, owing trol to be efiected on the train. If the track circuit is of small resistance beyond the signal S, the breaking of the short-circuit between M and N will not de-magnetize the relay R1 which will remain in operation until the train has passed through. The relay R will not need to operate. If, on the contrary, the track circuit is of some considerable resistance beyond the signal S, the opening by contact K1 of the short-circuit MN will efiect the excitation of the relay R and the ole-excitation of relay R1. As in the case of Figure 3, it will be necessary again to give suitable time constants to the two relays R. and R1. The arrangement will preferably be such that the relay R1 will be retarded in releasing in such manner that it only drops after the relay R. has operated. Under these conditions, the contact K will close before the contact K1 opens, and the contact K" will open before the contact K"1 again closes. The signal S will therefore remain excited and the control will be repeated on the locomotive until the train has passed the signal S.

With the arrangement according to Figure 4, as well as with that according to Figure 3, a large number of modifications may be made within the scope of the invention. For example, in both cases, the short-circuit of the track may be ensured not directly by the contacts of the relays R, R1 but by other suitable means, such as by the current which controls the signal itself, for example by means of a supplementary relay, or by a mechanical device carried by the signal S when the latter is in the form of a mechanical signal, this mechanical device becoming operative to short circuit the track at the end of the move ment of the signal.

It will further be understood that the invention is capable of numerous variations, as will be understood by one skilled in the art, resulting from the modifications of the means employed for carrying into practice the combinations of elements which constitute the essence of the invention. Thus, the types of relays, rectifiers, indicating devices and generators employed may also be varied within the scope of the invention which is limited only by the prior art and the scope of the appended claims.

What We claim and desire to secure by Letters Patent of the United States is:--

1. In a remote control system for railway installations, means for effecting a remote control action in advance of a vehicle travelling on the railway track and controlled from said vehicle, comprising means on the vehicle arranged to cooperate with means disposed on the track, said means on said vehicle comprising a source of alternating current and means for inducing electric current in the rails of said track, and said means disposed on said track comprising a first relay arranged to operate in accordance with the intensity of said electric current induced in said track, there being a voltage produced between the rails remotely from said vehicle by circulation of said electric current in said rails, a second relay arranged to operate in accordance with the voltage due to said electric current between the rails of said track, and means connected to be controlled upon operation of either of said relays to effect said control action.

2. In a control system for railway installations operated in accordance with the energization of the track, means disposed upon a vehicle traveling along the track for inducing an alternating electric current in the rails of said track so as to produce a voltage between said rails, means disposed on the track for effecting a control action in advance of said vehicle, comprising a first relay arranged to be operated in accordance with the current flowing in the track rails, a second relay arranged to be operated in accordance with the voltage due to said alternating electric current between said rails, and means connected to be controlled upon operation of either of said relays to effect said control action.

3. In a control system for railway installations operated in accordance with the energization of the track, means disposed upon a vehicle traveling along the track for inducing an alternating electric current in the rails of said track so as to produce a voltage between said rails, means disposed on the track for efiecting a control action in advance of said vehicle, comprising a first relay arranged to be operated in accordance with the current flowing in the track rails, a second relay arranged to be operated in accordance with the voltage due to said alternating electric current between said rails, and individual contact means connected to be controlled by each of said relays, said contact means being connected in circuit in such a manner that a control action is effected when either of said contact means is operated by the corresponding relay.

4. In a control system for railway installations operated in accordance with the energization of the track, means disposed upon a vehicle traveling along the track for inducing an alternating electric current in the rails of said track so as to produce a voltage between said rails, means disposed on the track for effecting a control action in advance of said vehicle, comprising a first relay arranged to be operated in accordance with the current flowing in the track rails, a second relay arranged to be operated in accordance with the voltage due to said alternating electric current between said rails, means connected to be controlled upon operation of either of said relays to effect said control action and means controlled by said relays to vary the impedance between the rails of said track when one of said relays is operated, in order to vary the current in the rails so as to transmit a return indication to the vehicle.

5. In a control system for railway installations operated in accordance with the energization of the track, means disposed upon a vehicle traveling along the track for inducing an alternating electric current in the rails of said track so as to produce a voltage between said rails, means disposed on the track for effecting a control action in advance of said vehicle, comprising a first relay arranged to be operated in accordance with the current flowing in the track rails, a second relay arranged to be operated in accordance with the voltage due to said alternating electric current between said rails, one of said relays being slow-releasing in comparison with the other of said relays, means connected to be controlled upon operation of either of said relays to effect said control action, and means controlled by said relays to vary the impedance between the rails of said track when one of said relays is operated, in order to vary the current in the rails so as to transmit a return indication to the vehicle.

6. In a control system for railway installations operated in accordance with the energization of the track, means disposed upon a vehicle traveling along the track for inducing an alternating electric current in the rails of said track so as to produce a voltage between said rails, means disposed on the track for effecting a control action in advance of said vehicle, comprising a first relay arranged to be operated in accordance with the current flowing in the track rails, a second relay arranged to be operated in accordance with the voltage due to said alternating electric current between said rails, individual contact means connected to be controlled by each of said relays, said contact means being connected in circuit in such a manner that a control action is effected when either of said contact means is operated by the corresponding relay, and further individual contact means connected to be controlled by each of said relays and in parallel with one another, said further contact means being connected to be closed when the corresponding relay is operated and being inserted in a lead short-circuiting said track rails, in order to vary the current in the rails so as to transmit a return indication to the vehicle.

'7. In a control system for railway installations operated in accordance with the energization of the track, means disposed upon a vehicle traveling along the track for inducing an alternating electric current in the rails of said track so as to produce a voltage between said rails, means disposed on the track for effecting a control action in advance of said vehicle, comprising a first relay arranged to be operated in accordance with the current flowing in the track rails, a second relay arranged to be operated in accordance with the voltage due to said alternating electric current between said rails, individual contact means con nected to be controlled by each of said relays, said contact means being connected in circuit in such a manner that a control action is effected when either of said contact means is operated by the corresponding relay, and further individual contact means connected to be controlled by each of said relays and inserted in series with one another in a lead short-circuiting normally said track rails, said further contact means being connected to be opened when the corresponding relay is opened to remove said short-circuit of said track rails, in order to vary the current in the rails so as to transmit a return indication to the vehicle.

ANDRE BECQ. PAUL NICOLAS. 

